javascript中利用数组实现的循环队列代码_javascript技巧

//循环队列
function CircleQueue(size){
this.initQueue(size);
}
CircleQueue.prototype = {
//初始化队列
initQueue : function(size){
this.size = size;
this.list = new Array();
this.capacity = size + 1;
this.head = 0;
this.tail = 0;
},
//压入队列
enterQueue : function(ele){
if(typeof ele == "undefined" || ele == ""){
return;
}
var pos = (this.tail + 1) % this.capacity;
if(pos == this.head){//判断队列是否已满
return;
}else{
this.list[this.tail] = ele;
this.tail = pos;
}
},
//从队列中取出头部数据
delQueue : function(){
if(this.tail == this.head){ //判断队列是否为空
return;
}else{
var ele = this.list[this.head];
this.head = (this.head + 1) % this.capacity;
return ele;
}
},
//查询队列中是否存在此元素，存在返回下标，不存在返回-1
find : function(ele){
var pos = this.head;
while(pos != this.tail){
if(this.list[pos] == ele){
return pos;
}else{
pos = (pos + 1) % this.capacity;
}
}
return -1;
},
//返回队列中的元素个数
queueSize : function(){
return (this.tail - this.head + this.capacity) % this.capacity;
},
//清空队列
clearQueue : function(){
this.head = 0;
this.tail = 0;
},
//判断队列是否为空
isEmpty : function(){
if(this.head == this.tail){
return true;
}else{
return false;
}
}
}